The invention relates to circuits having pronounced hysteresis in their input-output transfer function. Such circuits are commonly called Schmitt trigger circuits. Such circuits are useful in noise suppression and are widely used in relaxation oscillators. A CMOS Schmitt trigger circuit is disclosed and claimed in U.S. Pat. No. 3,984,703 to John M. Jorgensen and assigned to the assignee of the present invention. An input circuit is shown having a symmetrical hysteresis characteristic is followed by a latch and an output inverter.